EP1991447B1

EP1991447B1 - Crash protection system for a vehicle and a method for release and extension of a crash protection system for a vehicle

Info

Publication number: EP1991447B1
Application number: EP07715960.6A
Authority: EP
Inventors: Karl Kristian Berger; Roald Helland Pedersen
Original assignee: Benteler Automobiltechnik GmbH
Current assignee: Benteler Automobiltechnik GmbH
Priority date: 2006-02-27
Filing date: 2007-02-27
Publication date: 2013-06-19
Anticipated expiration: 2027-02-27
Also published as: EP1991447A1; WO2007097641A1

Description

Crash protection system for a vehicle and a method for release and extension of a crash protection system for a vehicle.
The present invention relates to active crash protection systems, particularly for vehicles such as passenger cars, and the way these systems are activated. The term "active" here refers to the protection systems being extended towards the impact, shortly before the impact takes place, following that the danger of impact has been detected and decided by an automatic sensing and governing system. In particular, the present invention relates to an improved system having a movable bar or beam, and a method for release and extension of the said bar or beam.
Systems with a movable roll over bar is known to be very useful for protecting the occupants in cars without protective roofs, in the case of having a roll over accident. DE 19781833 T1 discloses a common way of solving this.
A great number of crashes involve the front or rear structure of a car. Publication WO 97/47496 shows how a bumper system (beam) advantageously can be expanded in the direction of the crash shortly before the crash takes place.
In both cases the very useful effect of expanding the crash protection structure towards the crash is to create a longer or a higher vehicle to take the crash in a much better manner.
This invention is about a new and beneficial way of activating and expanding such systems, compared to the solutions hereto known. However the scope of the invention is not limited to front-, rear- and roll over crash protection systems. The solution may be used on crash protection structures in all directions that the car may be crashed or hit in an impact. One such direction may be sideways to the car, in the so-called side crash direction.
The effect of making the car structure longer is not only beneficial to the occupants of the car. It is well known, that in the case of a pedestrian being hit by the front of a car, the severity of the impact to the pedestrian may be lessened by adapting the car front crash structure to the situation. It may here be particularly useful for limiting the severity of damage to the knee and leg of the pedestrian by extending a low transverse "pedestrian beam" forward to first hit the lower part of the pedestrians leg. This invention is very well suited for defining a reliable such lower beam in a cost effective manner.
There are a great number of roll over protections systems (ROPS) provided with an extendable or deployable movable roll over bar suggested in the prior art. A common feature is a guiding regime controlling the position and deployment movement of the roll over bar. One of the topics in prior art is the struggle to ensure a successful release and deployment of the roll over bar even if the release or deployment of the bar is asymmetric. Problems similar to what is observed when a drawer is pulled out or pushed in asymmetrically, can occur and the increased resistance from the guides may slow down or completely prohibit the deployment of the roll over bar. This problem is in the following referred to as the jamming-effect (Schubladeneffekt). Geometrical variations (tolerances) in the car body, the roll over protecting system itself or the assembly process can lead to the same type of problems. The problems related to jamming-effect are increasing with increasing dimension of the deployable roll over bar in a direction perpendicular to the deployment direction. Therefore, some prior art in this area is focused on finding solutions for wide systems like roll over protection systems with one single roll over bar spanning a large part of the car width.
Another common topic in prior art is the release of the deployable roll over bar. Typically, the roll over bar is loaded by one or more pre-tensioned springs, and the system consists of one or more releasable locking devices which holds the roll over bar in a retracted position during normal use of the car and releases the roll over bar after receiving an electrical signal when a dangerous situation in which the roll over protection is needed is sensed by the car. Both electromagnetic and pyrotechnical versions of such devices are known and all the known devices contribute significantly to the cost of a ROPS. Some of the goals for new inventions in the ROPS area is to save cost and complexity by using only one releasable locking device (actuator) for each car.
DE 100 44 930 C1 shows a ROPS with a single, wide roll over bar spanning a large part of the car width and where the bar has two mainly vertical legs with a guiding system and deployment springs. A single releasable locking device is located in the middle of the bar, between the two legs. With this solution, the initial release of the system is symmetric, but jamming-effect caused by asymmetric effects due to tolerances in build and components used, such as guides and springs, are here not dealt with.
WO2004094197 (Karmann ) describes a ROPS with a single, wide roll over bar spanning a large part of the car width. An additional synchronisation mechanism is included to ensure an equal deployment of both sides. This solution will solve the jamming-problem, however with added complexity and cost.
DE 197 12 955 A1 describes a ROPS with a single, wide roll over bar spanning a large part of the car width. The roll over bar is divided in three parts, two vertical columns and a cross member, and the connections between the three have sufficient flexibility to avoid the "drawer-effect". This solution will also solve the jamming-problem but the extras joints in the roll over bar can be critical for the crash strength of the system and they causes additional cost and weight.
DE 195 40 819 A1 discloses a crash protection system according to the preamble of claim 1 having a roll bar. Said roll bar is connected to a pair of vertical extending side bars. To compensate production tolerances the bar is manufactured as a hinged beam, wherein the side bars are connected with the roll bar via pivots to develop linkages. Said linkages are made of an elastic damping material.
With the present invention there is provided a new solution, which deals with challenges as mentioned above in a robust and cost effective manner. In addition, the new solution is inherently robust with respect to tolerances of components and assembly processes. The new solution also offers good space utilisation, and an improved guiding system, avoiding the effects of jamming. With the proposed solution, the need for symmetry in the release and deployment of the roll over bar is removed. This give freedom in location of the releasable locking device and the deployment springs do not need to set up a symmetric force on the roll over bar. The roll over bar is manufactured as a single part without need for flexible joints which jeopardises the structural integrity in crash and increases manufacturing cost.
These and further advantages can be achieved in accordance with the present invention as defined in the accompanying claims.
In the following, the invention shall be further described by examples and figures where:

Fig. 1: discloses schematically in a perspective view an extendable roll over bar, in its protective, deployed position,
Fig. 2: discloses schematically in a rear view an extendable roll over bar, in its retracted position,
Fig. 3: discloses the roll over bar in the same view as of Fig. 2, when one side the bar is released and has completed a part of its deployment movement, and where the other side of the bar is still restrained in its retracted position and the entire bar is rotating about the upper right guide,
Fig. 4 Fig. 4: discloses the roll over bar in the same view as of Fig. 2 and 3 when the entire roll over bar has completed its deployment movement and is locked in its deployed, protective position,
Fig.5: discloses schematically an extendable protective structure, which is not part of the claimed invention.

Part list (for both embodiments)

A: Roll over protection system A' Extendable protective structure
1: Roll over bar
1': Crash protective structure
2: Releasable locking device
3, 3': Restraining hook
4, 4': Deployment springs
5, 5': Spring guide
6, 6': Deployment limiter
7, 7': Spring limiter
8: Rotation point guide
9, 9': Lower side guide
10, 10': Upper side guide
11, 11': Main housing
12, 12': Lower housing
14, 14': Locking Pawl
15, 15': Bolt for Locking Pawl
16, 16': Spring for Locking Pawl
17, 17': Spring Fixation
18, 18': Locking Pawl Bracket
19, 19': Shock Absorber
20, 20': Fixation for spring guide
21, 21': Upper Front/Rear Guide
22, 22': Bracket for Seat Belt Guide
23: Releasable hook
24, 24': Arresting fingers
25, 25': First crash release springs

The following description relates to one possible realisation of the invention in accordance with the following claims. The description describes a roll over protection system as shown in Figures 1-4 with a single, wide roll over bar 1 and two housing assemblies 11 ,11', 12, 12' connecting the roll over bar 1 with the car body. The roll over bar 1 can be brought from a lower, mainly hidden, retracted position to an upper protective position by means of the forces from pre-tensioned deployment springs 4, 4'.
The positions of the roll over bar in retracted and extended condition and the movement of the roll over bar between the two positions are controlled by means of a set of centring- and guiding devices 9, 9', 10, 10', 21, 21' fixed to the housings. The roll over bar is restrained in its retracted position by a releasable locking device 2 fixed to the housings 11 ,12 on one side, and a restraining hook 3 fixed to the housings 11', 12' on the opposite side.
In the upper, protective position, as shown in Figure 4, the roll over bar is prevented from being pushed back into the housings by means of two spring-loaded, rotating locking pawls 14, 14' engaging the bottom of the two vertical legs of the roll over bar. When the roll over bar has to be brought back into its retracted position, for instance after a test-release, the locking pawls can be rotated away from its engagement with the roll over bar, and the roll over bar is again free to be moved down.
The complete system is typically mounted into the car behind the rear seats. An advantage with this variant is the possibility to combine it with collapsible seatbacks and hence get the possibility to increase the luggage compartment of the car. This possibility is very limited when two separate roll over bars for each side of the car is used.
The mainly U-shaped roll over bar 1 preferably consist of a reformed aluminium profile, and it can be formed in one plane only or it can have a 3 dimensional shape. Other materials and processes can also be used.
The mainly vertically extended legs of the roll over bar are elastically centred in housings connected to the car body. The main housings 11, 11' transfer the forces from the roll over bar into the car body in case of a roll over incident. The use of extruded aluminium profiles for the main housing enables the direct integration of flanges for mounting to the car body, variable thicknesses for effective force transfer with minimum weight, possibility to include threads directly in the part itself etc. Other materials and processes can also be used.
It may be possible to integrate all necessary functions of the housing into one single part, or it may be more beneficial to introduce local reinforcements and extensions to take care of some functions. In this example, two lower housings 12, 12' are introduced below the main housing 11, 11' to provide support for additional components. The lower housings have lower requirements to transfer loads and can preferably be made from thinner material than the main housing to save cost and weight.
In the example described here, a separate bracket 18, 18' for fixation of the locking pawl 14, 14', its bolt 15, 15', spring 16, 16' and spring fixation 17, 17' is attached to the main housing. The locking pawl bracket can be made of an extruded aluminium profile welded to the main housing. For both the lower housings and the locking pawl bracket, other materials and processes can also be used.
The deployment of the roll over bar is driven and limited by a pair of springs 4, 4', supported by spring guides 5, 5' and spring limiters 7, 7' located inside the legs or columns of the roll over bar. The spring limiters 7, 7' are fixed inside the columns of the roll over bar, preferably by plastic deformation of the walls of the roll over bar into grooves on the outside of the spring limiters, and have central holes large enough for the spring guides to pass through but too small for the deployment springs. The lower ends of the spring guides are fixed to the bottom of the housing so that he spring forces acts between the housing and the deployable roll over bar.
A space-saving feature implemented in this solution is the use of the spring guiding system to limit the deployment of the roll over bar. The upper end of the spring guides 5, 5' are equipped with deployment limiters 6, 6' which the spring limiters 7, 7' hit when a certain deployment length is reached. The fixations 20, 20' of the spring guides 5, 5' to the housing 12, 12' are equipped with shock absorbers 19, 19' to limit the impact forces on the system when the deployment is stopped.
The release and deployment sequence of the roll over bar is described in the following based on Figures 2-4.
In Figure 2, the roll over bar 1 is locked in its retracted position by the restraining hook 3 on one side and the releasable locking device 2 on the other side. A releasable hook 23 has one end fixed to the roll over bar and the other end is secured in the releasable locking device 2. The connection of the releasable hook 23 to the roll allow limited rotations so that the connection can absorb the manufacturing variations of the roll over bar and the housing. The roll over bar is kept in position by the elastic support from the guides 9, 9', 10, 10', 21, 21' all acting on the outside of the bar. There is free space between the springs 4, 4' and spring guides 5, 5' and the Inside the roll over bar so no support or guiding is provided there.
Figure 3 shows the roll over protection system A in the pre-release phase shortly after the release of the releasable locking device. The spring force from 4 has caused the released side of the roll over bar to start its deployment. On the other side, the roll over bar is kept down by the restraining hook 3, and the roll over bar has started to rotate in its own main plane of extension. Higher up on the restrained side, the roll over bar is in contact with the rotation point guide 8 which transfers the rotation of the bar resulting from the mainly vertical deployment of the released side into a mainly horizontal movement of the lower end of the not released side of the roll over bar. The not released side of the bar hence starts to slide off the restraining hook 3. When the deployment of the released side and the resulting rotation has brought the roll over bar completely free from the restraining hook, the bar is fully released and free to complete its deployment.
Figure 4 shows the roll over protection system A when the entire roll over bar has completed its deployment movement and is locked in its deployed, protective position. The locking pawls 14, 14' have rotated into engagement with the lower ends of the roll over bar and prevents it from being pushed down again when subjected to crash loads.
A roll over protection system designed according to the principles above can be made very robust regarding tolerances of the car body, the roll over bar and the assembly process by including sufficient air gap between the roll over bar 1 and the housing assemblies 11, 11', 12, 12'. However, it may be beneficial to eliminate some of the variations to minimize the space needed for the roll over protection system in the car. In this case, a combination of tailor-made transport containers and precisely defined handling-devices could be used to ensure a well defined position of the two housing assemblies to another when the system is assembled into the car body. In particular, there may be significant variations in the width of car body which influence can be eliminated.
The roll over protection bar of the examples is shown as mainly U-shaped, i.e. a top down "U" with one pair of substantially vertically arranged columns or legs.
The roll over protection bar in accordance with the present invention may cover practically the whole width of the vehicle by the arrangement of a single wide bar, or there may be arranged plural units in a side by side manner.
Further, the example shows a system where each side of the roll over bar is guided and supported in individual, not connected housings. However, it should be understood that the principles of the present invention can be applied also is cases where the housings are connected with one or more additional cross members or if the roll over protection system is part of an integrated module with other functions like body stiffness, mounting base for seats, headrests, interior trim etc.
Figure 5 shows schematically an extendable protective structure A' which is not part of the claimed invention. Here, the actuator (releasable locking device) 2 is holding the moveable, protective structure 1' on one side in a transverse, or semi-transverse direction to the main legs of the protective bar. Said direction is defined by the angle "[alpha]" (alpha) of the restraining hooks 3, 3', arresting the system in the main extension direction through interacting with the arresting fingers 24, 24' fixed to the bar. The restraining hooks 3, 3' together with the components of the system are preferably arranged within housings 11, 11'. The first crash release springs 25, 25' ensure the initial movement in the first releasing direction, leading to the full release of the system in the main extension direction, driven by the deployment springs 4, 4'. Both the first releasing movement as well as the main extension movement are translatoric.
Another embodiment could imply that one leg of a U-shaped deployable structure is allowed to move in a first transverse direction relative the length axis of the leg. This movement will be similar to the pre-release movement discussed above, and can be generated by the activation of a releasable locking device.
This pre-release movement will cause a rotation about the similar axis of the other leg.

Claims

Crash protection system for a vehicle such as a passenger car, comprising at least one protective bar (1) having one pair of substantially vertically arranged columns, said bar (1) is movably arranged in the vehicle for being moved from a first retracted position to a second extended position, wherein said bar (1) is locked in its retracted position by a restraining hook (3) on one side and is provided with means for its pre-release, causing it to move towards a first position, and that the bar (1) is completely released and allowed to move to its extended position as the first, pre-released position is achieved, characterised in that the protective bar (1) and his pair of columns are manufactured as a single part, so that said bar (1) is mainly U-shaped, said bar (1) is also locked in its retracted position on the other side by a releasable locking device (2) as a mean for its pre-release, wherein said bar (1) is in contact with a rotation point guide (8) located higher upon the side of the restraining hook (3) to swivel said bar (1) around said rotation point guide (8) and to release the column from the restraining hook (3).
Crash protection system in accordance with claim 1, characterised in that a major component of the said pre-release movement is in a direction transversal versus the direction of extension.
Crash protection system in accordance with claim 1, characterised in that a major component of the said pre-release movement is a rotation substantially in the plane of extension.
Crash protection system in accordance with claim 3, characterised in that a set of restraint and support points define the said movement in such a way that when one side of the protective bar (1) has completed a sufficient part of its deployment movement, the other side of the bar (1) is released through a movement mainly perpendicular to the deployment direction, and the entire protective bar (1) is free to complete its deployment.
Crash protection system in accordance with claim 1, characterised in that the rotation point guide (8) has limited flexibility.
Crash protection system in accordance with claim 5, characterised in that the protective bar (1) is prevented from accidental release from its restraining hook (3) by means of a guide (9', 10') with limited flexibility located at the outside and around the inner end of the protective bar (1) on the opposite side as the restraining hook (3).
Crash protection system in accordance with claim 1, characterised in that the releasable locking device (2) is located on the inside of the protective bar (1) at the opposite side as the restraining hook (3) and connected to the bar (1) by means of a connection element mainly capable of transferring axial loads.
Crash protection system in accordance with claim 1, characterisedin that an assembly of deployment springs (4, 4') with guides (5, 5') and limitators (6, 6', 7, 7') are mounted inside one column of the protective bar (1) in such a way that they do not provide any guidance or limitation for the deployment movement of the protective bar (1).
Crash protection system in accordance with claim 8, characterised in that the spring guides (5, 5') and spring limitators (6, 6', 7, 7') inside the columns of the protective bar (1) also serves as limitators for the deployment movement.
Crash protection system in accordance with claim 1, characterised in that the inner end of the columns of the protective bar (1) are used as for a spring-loaded rotational latch locking the roll over bar (1) in its deployed, protective position.
Crash protection system in accordance with claim 1, characterised in that the protective bar or beam is arranged in the vehicle for roll over protection.
Crash protection system in accordance with claim 1, characterised in that components of the system are arranged in at least one main housing (11, 11'), where the upper part of the main housing (11,11') serves a fixing point for a seat belt guide.
Crash protection system in accordance with claim 1, characterised in that the protective bar (1) is arranged in the vehicle for front, rear or lateral protection.
Crash protection system in accordance with claim 1, characterised in that the protective bar (1) is arranged in the vehicle as a pedestrian protective means.
A method for release and extension of a crash protection system for a vehicle, such as a passenger car, the system comprising a roll over protection bar (1) with at least one pair of substantially vertically arranged columns connected with the protective bar (1), wherein said bar (1) is movably arranged in the vehicle for being moved from a first retracted position to a second extended, protective position, wherein said bar (1) will be locked in its retracted position by a restraining hook (3) on one side, characterised in that the bar (1) and his pair of columns are manufactured as a single part, so that said bar (1) is mainly U-shaped, wherein said bar (1) will also be locked in its retracted position by a releasable locking device (2) on the other side, said bar (1) is in contact with a rotation point guide (8) located higher upon the side of the restraining hook (3), wherein releasing said bar (1) of the releasable locking device (2) will swivel said bar (1) around said rotation point guide (8) so that the bar (1) is pre-released and allowed to move to a first position, whereby said bar (1) when achieving a predefined position will be fully released from the restraining hook (3) and subsequently moves to its extended position.
A method in accordance with claim 15, characterised in that a major component of the said pre-release movement is in a direction lateral versus the direction of extension.
A method in accordance with claim 15, characterised in that a major component of the said pre-releasing movement is constituted by a rotation of the protective bar (1) in its main plane of movements from retracted to extended position.
A method in accordance with claim 15, characterised in that a major component of the said pre-releasing movement is constituted by a rotation of the protective bar (1) about an axis parallel to its direction of movements from retracted to extended position.
A method in accordance with claim 15, characterised in that a set of restraint and support points define the said pre-releasing movement in such a way that when one side of the protective bar (1) has completed a sufficient part of its deployment movement, the other side of the bar (1) is released through a movement mainly perpendicular to the deployment direction, and the entire bar (1) is free to complete its deployment.